The main objective of this thesis is to introduce a four perspectives structure in order to provide one solution for traceability and dependability in the system design phase. The traceability between different perspectives help engineers have a clear picture of the whole system before goes to the real implementation.  Fuel Level Display system from Scania Truck is used to undertake as a case study to offer insights of the approach. A four perspectives structure is made in the first place in order to analysis traceability between different viewpoints. After implementing the Fuel Level Display system in Modelica, a verification scenario is specified to perform a complete requirement verification process for system design against requirements.

This dissertation supports human decision-making with a Model-Based Systems Engineering methodology enabling engineering analysis, and in particular Operations Research analysis of discrete-event logistics systems, to be more widely used in a cost-effective and correct manner. A methodology is a collection of related processes, methods, and tools, and the process of interest is posing a question about a system model and then identifying and building answering analysis models. Methods and tools are the novelty of this dissertation, which when applied to the process will enable the dissertation's goal. One method which directly enables the goal is adding automation to analysis model-building. Another method is abstraction, to make explicit a frequently-used bridge to analysis and also expose analysis model-building repetition to justify automation. A third method is formalization, to capture knowledge for reuse and also enable automation without human interpreters. The methodology, which is itself a contribution, also includes two supporting tool contributions. A tool to support the abstraction method is a definition of a token-flow network, an abstract concept which generalizes many aspects of discrete-event logistics systems and underlies many analyses of them. Another tool to support the formalization method is a definition of a well-formed question, the result of an initial study of semantics, categories, and patterns in questions about models which induce engineering analysis. This is more general than queries about models in any specific modeling language, and also more general than queries answerable by navigating through a model and retrieving recorded information. A final contribution follows from investigating tools for the automation method. Analysis model-building is a model-to-model transformation, and languages and tools for model-to-model transformation already exist in Model-Driven Architecture of software. The contribution considers if and how these tools can be re-purposed by contrasting software object-oriented code generation and engineering analysis model-building. It is argued that both use cases share a common transformation paradigm but executed at different relative levels of abstraction, and the argument is supported by showing how several Operations Research analyses can be defined in an object-oriented way across multiple layered instance-of abstraction levels. Enabling Operations Research analysis of discrete-event logistics systems to be more widely used in a cost-effective and correct manner requires considering fundamental questions about what knowledge is required to answer a question about a system, how to formally capture that knowledge, and what that capture enables. Developments here are promising, but provide only limited answers and leave much room for future work.

Yes / The rapid progress of the Internet of Things (IoT) has continued to offer humanity numerous benefits, including many security and safety-critical applications. However, unlocking the full potential of IoT applications, especially in high-consequence domains, requires the assurance that IoT devices will not constitute risk hazards to the users or the environment. To design safe, secure, and reliable IoT systems, numerous frameworks have been proposed to analyse the safety and security, among other properties. This paper reviews some of the prominent classical and model-based system engineering (MBSE) approaches for IoT systems’ safety and security analysis. The review established that most analysis frameworks are based on classical manual approaches, which independently evaluate the two properties. The manual frameworks tend to inherit the natural limitations of informal system modelling, such as human error, a cumbersome processes, time consumption, and a lack of support for reusability. Model-based approaches have been incorporated into the safety and security analysis process to simplify the analysis process and improve the system design’s efficiency and manageability. Conversely, the existing MBSE safety and security analysis approaches in the IoT environment are still in their infancy. The limited number of proposed MBSE approaches have only considered limited and simple scenarios, which are yet to adequately evaluate the complex interactions between the two properties in the IoT domain. The findings of this survey are that the existing methods have not adequately addressed the analysis of safety/security interdependencies, detailed cyber security quantification analysis, and the unified treatment of safety and security properties. The existing classical and MBSE frameworks’ limitations obviously create gaps for a meaningful assessment of IoT dependability. To address some of the gaps, we proposed a possible research direction for developing a novel MBSE approach for the IoT domain’s safety and security coanalysis framework.

Yes / The Internet of Things (IoT) paradigm has continued to provide valuable services across various domains. However, guaranteeing the safety assurance of the IoT system is increasingly becoming a concern. While the growing complexity of IoT design has brought additional safety requirements, developing safe systems remains a critical design objective. In earlier studies, a limited number of approaches have been proposed to evaluate the safety requirements of IoT systems through the generation of static safety artefacts based on manual processes. This paper proposes a model-based approach to the safety analysis of the IoT system. The proposed framework explores the expressiveness of UML/SysML graphical modelling languages to develop a dynamic fault tree (DFT) as an analysis artefact of the IoT system. The framework was validated using a hypothetical IoT-enabled Smart Fire Detection and Prevention System (SFDS). The novel framework can capture dynamic failure behaviour, often ignored in most model-based approaches. This effort complements the inherent limitations of existing manual static failure analysis of the IoT systems and, consequently, facilitates a viable safety analysis that increases public assurance in the IoT systems. / The full text of this accepted manuscript will be available at the end of the publisher's embargo: 11th Feb 2025

Indiana University-Purdue University Indianapolis (IUPUI) / Mass customization, small lot sizes, reduced cost, high variability of product types and changing product portfolio are characteristics of modern manufacturing systems during life cycle. A direct consequence of these characteristics is a more complex system and supply chain. Product lifecycle management (PLM) and model based system engineering (MBSE) are tools which have been proposed and implemented to address different aspects of this complexity and resulting challenges. Our previous work has successfully implemented a MBSE model into a PLM platform. More specifically, Pattern based system engineering (S* pattern) models of systems are integrated with TEAMCENTER to link and interface system level with component level, and streamline the lifecycle across disciplines. The benefit of the implementation is two folded. On one side it helps system engineers using system engineering models enable a shift from learning how to model to implementing the model, which leads to more effective systems definition, design, integration and testing. On the other side the PLM platform provides a reliable database to store legacy data for future use also track changes during the entire process, including one of the most important tools that a systems engineer needs which is an automatic report generation tool. In the current work, we have configured a PLM platform (TEAMCENTER) to support automatic generation of reports and requirements tables using a generic Oil Filter system lifecycle. There are three tables that have been configured for automatic generation which are Feature definitions table, Detail Requirements table and Stakeholder Feature Attributes table. These tables where specifically chosen as they describe all the requirements of the system and cover all physical behaviours the oil filter system shall exhibit during its physical interactions with external systems. The requirement tables represent core content for a typical systems engineering report. With the help of the automatic report generation tool, it is possible to prepare the entire report within one single system, the PLM system, to ensure a single reliable data source for an organization. Automatic generation of these contents can save the systems engineers time, avoid duplicated work and human errors in report preparation, train future generation of workforce in the lifecycle all the while encouraging standardized documents in an organization.

La modélisation informatique et la simulation sont des activités de plus en plus répandues lors de la conception de systèmes complexes et critiques tels que ceux embarqués dans les avions. Une proposition pour la conception et réalisation d'abstractions compatibles avec les objectifs de simulation est présentée basés sur la théorie de l'informatique, le contrôle et le système des concepts d'ingénierie. Il adresse deux problèmes fondamentaux de fidélité dans la simulation, c'est-à-dire, pour une spécification du système et quelques propriétés d'intérêt, comment extraire des abstractions pour définir une architecture de produit de simulation et jusqu'où quel point le comportement du modèle de simulation représente la spécification du système. Une notion générale de cette fidélité de la simulation, tant architecturale et comportementale, est expliquée dans les notions du cadre expérimental et discuté dans le contexte des abstractions de modélisation et des relations d'inclusion. Une approche semi-formelle basée sur l'ontologie pour construire et définir l'architecture de produit de simulation est proposée et démontrée sur une étude d'échelle industrielle. Une approche formelle basée sur le jeu théorique et méthode formelle est proposée pour différentes classes de modèles des systèmes et des simulations avec un développement d'outils de prototype et cas des études. Les problèmes dans la recherche et implémentation de ce cadre de fidélité sont discutées particulièrement dans un contexte industriel. / In using Modeling and Simulation for the system Verification & Validation activities, often the difficulty is finding and implementing consistent abstractions to model the system being simulated with respect to the simulation requirements. A proposition for the unified design and implementation of modeling abstractions consistent with the simulation objectives based on the computer science, control and system engineering concepts is presented. It addresses two fundamental problems of fidelity in simulation, namely, for a given system specification and some properties of interest, how to extract modeling abstractions to define a simulation product architecture and how far does the behaviour of the simulation model represents the system specification. A general notion of this simulation fidelity, both architectural and behavioural, in system verification and validation is explained in the established notions of the experimental frame and discussed in the context of modeling abstractions and inclusion relations. A semi-formal ontology based domain model approach to build and define the simulation product architecture is proposed with a real industrial scale study. A formal approach based on game theoretic quantitative system refinement notions is proposed for different class of system and simulation models with a prototype tool development and case studies. Challenges in research and implementation of this formal and semi-formal fidelity framework especially in an industrial context are discussed.

Indiana University-Purdue University Indianapolis (IUPUI) / The internal and external interactions between the complex structural and behavioral characteristics of the system of interest and the surrounding environment result in unpredictable emergent behaviors. These emergent behaviors are not well understood, especially when modeled using the traditional top-down systems engineering approach. The intrinsic nature of current complex systems has called for an elegant solution that provides an integrated framework in Model-Based Systems Engineering. A considerable gap exists to integrate system engineering activities and engineering analysis, which results in high risk and cost. This thesis presents a framework that incorporates indefinite and definite modeling aspects that are developed to determine the complexity that arises during the development phases of the system. This framework provides a workflow for modeling complex systems using Systems Modeling Language (SysML) that captures the system’s requirements, behavior, structure, and analytical aspects at both problem definition and solution levels. This research introduces a new level/dimension to the framework to support engineering analysis integrated with the system architecture model using FMI standards. A workflow is provided that provides the enabling methodological capabilities. It starts with a statement of need and ends with system requirement verification. Detailed traceability is established that glues system engineering and engineering analysis together. Besides, a method is proposed for predicting the system’s complexity by calculating the complexity index that can be used to assess the complexity of the existing system and guide the design and development of a new system. To test and demonstrate this framework, a case study consisting of a complex district cooling system is implemented. The case study shows the framework’s capabilities in enabling the successful modeling of a complex district cooling system. The system architecture model was developed using SysML and the engineering analysis model using Modelica. The proposed framework supports system requirements verification activity. The analysis results show that the district chiller model developed using Modelica produces chilled water below 6.6 degrees Celsius, which satisfies the system requirement for the district chiller system captured in the SysML tool. Similarly, many such requirement verification capabilities using dynamic simulation integration with the high-level model provides the ability to perform continuous analysis and simulation during the system development process. The systems architecture complexity index is measured for the district cooling case study from the black-box and white box-perspective. The measured complexity index showed that the system architecture’s behavioral aspect increases exponentially compared to the structural aspect. The systems architecture’s complexity index at black-box and white-box was 4.998 and 67.3927, respectively.

<p>The accelerating digital transformation in the aerospace and defense sectors underlines a pressing need for refined, standardized methodologies for integrating digital tools into mission engineering (ME).  Existing literature reveals a distinct gap in the practical application of Digital Engineering (DE) and Model-Based Systems Engineering (MBSE) within ME, particularly due to the lack of clear guidelines for implementation. Recognizing DE and MBSE's potential to manage complex systems, this thesis puts forth a novel DE framework specifically designed for ME to streamline digital tool integration.</p> <p><br></p> <p>The research approach includes a thorough literature review, the development and application of a unique framework for an active debris remediation mission, and the examination of case studies. The findings inform the ongoing digital transformation efforts in the defense and aerospace sectors, offering valuable insights into the real-world application of DE and MBSE within ME. This study focuses on the early-stage, holistic-view design processes of mission and system-of-systems, aiming to establish a robust foundation for detailed lower-level engineering design.</p> <p><br></p> <p>By exploring how to leverage current practices to develop a framework that supports digital artifacts and tools, assessing the framework's improvements, and exploring possible quantification of its impact, this thesis charts a path toward the successful execution of complex mission objectives in the digital era.</p>

L'interopérabilité entre les systèmes a été identifiée comme un problème majeur auquel sont confrontées les entreprises lorsqu’ils ont le besoin de collaborer avec d'autres organisations et de participer au sein d’un réseau d’entreprises. Pour atteindre une qualité d'interopérabilité supérieure et garantir une collaboration efficace, un certain nombre d'Exigences d'Interopérabilité (EI) doivent être satisfaites. Ainsi, l'interopérabilité doit être vérifiée et continuellement améliorée. L’Analyse de l’Interopérabilité (ANIN) est une manière de vérifier l’interopérabilité des systèmes. Cependant, en général, la notion « d’exigence » est implicite et présentée sous forme de critères d'évaluation dans les approches ANIN. Il a également été identifié que les interdépendances entre les EI ne sont pas explicitement définies. En effet, leurs interdépendances doivent être prises en compte car elles peuvent aider à identifier les impacts sur l'ensemble du système. De plus, la majorité des approches ANIN sont manuelles, ce qui est un processus laborieux et long qui dépend souvent des connaissances « subjectives » des experts. Dans ce contexte, cette recherche propose un Système d'Analyse de l'Interopérabilité basé sur la Connaissance (SAIC) pour soutenir la prise de décision au sein des entreprises en réseau. Une méthodologie « Design Science Research » (DSR) a été adoptée pour mener à bien la contribution proposée. Premièrement, une approche basée sur l’ingénierie des exigences a été adaptée pour obtenir des EI pertinentes, établir un lien entre les EI obtenues et les composantes du système concerné et définir les interdépendances entre les EI. Pour conceptualiser formellement les connaissances sur l’ANIN, en englobant l'ensemble des EI, les problèmes et solutions d'interopérabilité ainsi que leurs relations, nous avons proposé l’Ontologie de l'Analyse de l'Interopérabilité (OAI). Une approche d'Ingénierie Système basée sur des Modèles a été appliquée pour définir les concepts de l'ontologie. Un prototype du SAIC utilisant l'OAI comme modèle de connaissance a été développé sur une plate-forme Java. L'outil résultant peut exploiter les connaissances sur l'interopérabilité et les informations provenant de la situation actuelle des systèmes évalués pour identifier les problèmes et améliorations potentiels. La contribution proposée a été évaluée grâce à une étude de cas basée sur une véritable entreprise en réseau / Enterprise systems’ interoperability has been identified as a significant issue faced by enterprises, which need to collaborate with other companies and participate within Networked Enterprises. To achieve a higher quality of interoperability and ensure an effective collaboration, a certain number of Interoperability Requirements (IRs) should be satisfied. Thus, interoperability should be verified and continuously improved. A manner for verifying the enterprise systems’ interoperability is through the Interoperability Assessment (INAS). However, in general, the notion of “requirement” is implicit and presented as Interoperability Evaluation Criterion (IEC) in the INAS approaches. It also has been identified that the IEC interdependencies are not explicitly defined. Indeed, their interdependencies should be considered as they can support the identification of impacts on the overall system. Further, the majority of the INAS approaches are manual-conducted, which is a laborious and time-consuming process and in many times depends on the “subjective” knowledge of experts, which can be expensive in time and money when hiring external consultants. In this context, this research proposes a Knowledge-Based Interoperability Assessment System (KBIAS) for supporting decision-making within Networked Enterprises. A Design Science Research (DSR) methodology has been adopted for conducting the work. First, A Requirement Engineering (RE) approach has been adapted to elicit and define relevant IRs, which are father related with system’s components. Such IRs are used as IEC during the INAS process. To formally conceptualise the knowledge about the INAS (subsuming the set of IRs, interoperability problems and solutions), we proposed the Ontology of Interoperability Assessment (OIA). A Model-Based System Engineering approach has been applied for defining and organising the concepts of the proposed ontology. A prototype of the KBIAS using the OIA as its knowledge model has been developed in a Java platform. The developed tool can exploit the knowledge about interoperability issues and information from the as-is situation of the assessed systems for identifying potential problems and improvements. The contribution proposed in this research has been evaluated through a case study based on a real Networked Enterprise

L'organisation classique en silos disciplinaires des industries atteint ses limites pour maîtriser la complexité. Les problèmes sont découverts trop tard et le manque de communication entre les experts empêche l'émergence précoce de solutions. C'est pourquoi, il est urgent de fournir de nouvelles approches collaboratives et des moyens d' interactions entre les disciplines d'ingénierie, au début et tout au long du cycle de développement. Dans ce contexte, nous avons étudié l'approche synchronisation de modèles entre deux domaines d'ingénierie : la conception d'architecture de systèmes et la sûreté de fonctionnement. Elle a pour but de construire et maintenir la cohérence entre les modèles.Ces travaux proposent, étudient et analysent une démarche collaborative de synchronisation de modèles. Ils tiennent compte des contextes d’études, des processus, des méthodes appliqués et des points de vue produits par les ingénieurs. Les contributions répondent à des problématiques au niveau des pratiques, des concepts, de la mise en œuvre, des applications et l’implémentation de la synchronisation de modèles. / Classical organization in disciplinary silos in the industry reaches its limits to manage and control complexity. Problems are discovered too late and the lack of communication between experts prevents the early emergence of solutions. This is why it is urgent to provide new collaborative approaches and ways to exchange the models contents between various engineering fields, early and all along the development cycle. In this context, we are particularly interested in a synchronization approach of models between two engineering fields: system architecture design and dependability analysis.This work proposes a collaborative approach of synchronization of models. It takes into account the study contexts, applied processes, applied methods and viewpoint produced by engineers. Contributions address issues at levels of practices, concepts, implementation, applications and implementation of model synchronization.